S-Video Out vs. 3 RCA Jacks

Discussion in 'Amateur Video Production' started by TC, Jan 15, 2004.

  1. TC

    TC Guest

    What is the difference? My DVD player has both. I'm currently using
    the RCA jacks with my ADVC-100 but wondering if I should be using the
    S-Video plug.
     
    TC, Jan 15, 2004
    #1
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  2. s vhs supposed to be higher video quality
     
    Steve Friedman, Jan 15, 2004
    #2
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  3. The RCA jack (yellow = "composite video") contains both
    the "luminance" (aka "Y") or black & white detail of the
    picture mixed together with the color (aka "chroma" or "C")
    part. This is why the 4-pin mini-DIN connector is also known
    as "Y/C".

    The advantage of using Y/C (vs. composite) is that you bypass
    the artifacts that are caused by separating the luminance from
    the chroma signals.
    Using Y/C is virtually always preferable (better picture
    quality) than using composite. If you have any doubts, try it
    both ways and see if YOU see a difference on YOUR TV.

    Note that ONLY the COMPOSITE VIDEO signal (the yellow
    RCA jack carries video. The white and red carry the audio and
    are NOT replaced by using the Y/C video interconnect.
     
    Richard Crowley, Jan 15, 2004
    #3


  4. You took the words right out of my mouth!

    actually i did not recall exactly why
     
    Steve Friedman, Jan 15, 2004
    #4
  5. TC

    A Good Joe Guest

    The advantage of using Y/C vs. Composite is that you bypass the artifacts
    that are caused by mixing, not separating, the luminance with, not from, the
    chroma signals.
     
    A Good Joe, Jan 15, 2004
    #5
  6. TC

    Will Dormann Guest


    Depends on what you mean by "3 RCA Jacks"

    If they're yellow, white, and red then that's composite video plus
    stereo audio, and lower quality than S-Video.

    If they're green, blue, and red then that's component video, and higher
    quality than S-Video.




    -WD
     
    Will Dormann, Jan 15, 2004
    #6
  7. TC

    JB Guest

    Is the S-VIDEO cable for video only ?

    Do I still use the red/white rca jacks for audio ?
     
    JB, Jan 15, 2004
    #7
  8. TC

    Will Dormann Guest


    S-Video is for <drumroll, please> .... Video.

    If you want audio to go along with it, you'll need to hook up the rca
    connectors for that.


    -WD
     
    Will Dormann, Jan 15, 2004
    #8
  9. "A Good Joe" wrote ...
    It is almost trivial to mix the signals. It is much more complex
    to separate them without doing damage to Y, C (or both).
    High-end equipment uses sophisticated methods like comb
    filters and surface acoustic-wave (SAW) devices to attempt
    to separate Y and C with minimal destruction of the video.
     
    Richard Crowley, Jan 15, 2004
    #9
  10. Good call! "TC" didn't state which he meant by "3 RCA jacks"

    Yellow = composite video
    White = left channel audio
    Red = right channel audio

    or

    Red = red component video
    Blue = blue component video
    Green = green component video (including sync
    unless there are additional connectors for sync)

    White, black, brown (sometimes even yellow)
    are used for either separate composite sync, or
    for separate horizontal and vertical sync. The
    color coding for separate sync is not as standardized
    as the R,G, and B components.

    There are also some quasi-standards for
    Y, Pb, Pr (a different, lower quality, form of component video)
     
    Richard Crowley, Jan 15, 2004
    #10
  11. TC

    TC Guest

    I didn't know there were others ;) But I meant the R/Y/W jacks.
    Thanks all for the input!
     
    TC, Jan 15, 2004
    #11
  12. TC

    TC Guest

    Ok. Just to confirm. S-Video is better to use. However, you must
    also use the Red & Which RCA plugs along with it to get sound?
     
    TC, Jan 15, 2004
    #12
  13. TC

    Will Dormann Guest


    Yes.

    -WD
     
    Will Dormann, Jan 15, 2004
    #13
  14. TC

    david.mccall Guest

    It's known by several names, but I've never been sure how different
    the different flavors really are. They seem pretty interchangeable, even
    more so than Firewire, iLink, and 1394 are.

    These days Component usually refers to YUV; Y, Pb, Pr; Y, B-Y, R-Y; etc

    RGB & GBR are also referred to as component (it used to be used in studios
    for chroma keying, and in most lab applications), but it is becoming rare
    (except for computer monitors). And yes it is better quality in terms of
    color
    space, but there are no "off the shelf" recorders that can record RGB,
    making
    it not real useful in a production environment. YUV component formats nearly
    all compress the chroma portion of the signal (most often heavy
    compression).

    Even Betacam SP (an analog format) compresses the color components when
    recording to tape. The Y channel gets recorded full frame, but the 2 color
    components are compressed horizontally and placed side by side.

    Indeed DVD players do come with Y, Pb, Pr component outputs, but the
    RCA jacks are Y=green jack Pb=blue jack Pr=red jack

    David
     
    david.mccall, Jan 16, 2004
    #14
  15. TC

    david.mccall Guest

    You are both right, for the most part. The artifacts are caused
    by the damage introduced at the creation of the composite signal.
    The color information is encoded into a variable voltage that
    represents the hue, and another that represents the color level.
    these 2 signals are used to modulate the color subcarrier
    (~3.58mhz). The higher the color level, the greater the amplitude
    of the subcarrier, also the hue signal is phase modulated onto
    the same subcarier. The result of this (plus the color burst) is the
    "C" part of Y/C video.

    To create a composite signal, the Y (contains all detail and
    luminance information) is frequency limited to something less
    than the subcarrier (essentially a slight blurring) to keep detail
    from being interpreted as color information, Then the color
    information and the luminance information is mixed together
    to create the composite signal.

    Obviously, you can never recover the detail that was removed,
    and there will always be some interaction between the 2 signals.
    These artifacts cannot be removed, but fancy filters in the
    decoding process can limit it to some extent.

    So yes, the damage is caused at the time of encoding the
    composite signal, and yes, comb filters and surface
    acoustic-wave filters can help clean up the artifacts,
    and may introduce some minor artifacts of their own.

    David
     
    david.mccall, Jan 16, 2004
    #15
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